1. Field of the Invention
The present invention relates to an electronic device having an audio output unit. More particularly, present invention relates to an electronic device having an audio output unit and issues related to audio speakers in portable electronic devices.
2. Description of the Related Art
In general, portable electronic devices refer to devices that are carried by a user and allow the user to access a variety of content, such as portable terminals, MP3 players, Portable Multimedia Players (PMPs), electronic books, Personal Digital Assistants (PDA's), tablets and the like.
The proliferation of such portable electronic devices has become more diversified over time in terms of form factors according to purposes thereof, periodical changes, the demands of consumers, and the like. Recently, use of bar type portable terminals containing a variety of functions, such as smart phones or tablet PCs, is increasing.
Portable electronic devices are frequently used while in motion due to easy portability thereof and various functions loaded therein. However, the use of such devices while the user is in motion causes a number of problems, such as damage to portable electronic devices when they fall, bend, twist or the like depending on environments in which portable electronic devices are carried, and other deformations. Such devices can be left in automobiles and exposed to extreme heat or cold, and used outdoors in the rain, etc., thereby stressing nearly all aspects of operation of these portable electronic devices.
In an attempt to solve some of the above-described problems, various technologies have been developed. In one example, during injection molding of a case for portable electronic devices, reinforcing ribs may be formed at opposite side surfaces of the case, or reinforcing members may further be installed. Related technology with regard to installation of the reinforcing members is disclosed in, for example Korean Patent Registration No. 10-0810375 (registered on Feb. 27, 2008 and entitled “Reinforcing Device for Slim Portable Terminal”).
In another example, the materials used by manufacturers to construct the cases of portable electronic devices have changed from polycarbonate (PC) to composites of polycarbonate and glass fiber (GF), polyphthalamide or the like, in order to reinforce the cases of the portable electronic devices. Related technology with regard to this material change is disclosed in Korean Patent Laid-Open Publication No. 10-2010-0058337 (published on Jun. 3, 2010 and entitled “Painting Composition for Portable Electronic Device and Painting Method Using the Same”).
However, even if reinforcing ribs are formed at opposite side surfaces of a case of a portable electronic device during injection molding of the case, the rigidity of the case is not greatly increased, e.g., increased by about 10%, and thus, the reinforced-rib case still may be easily deformed due to an external force.
Moreover, due to the fact that the reinforcing ribs are densely formed at opposite side surfaces of the case, the mold may be subjected to undesirable engagement during injection molding of the case. Additionally, since the interior space of the case provided with the densely formed reinforcing ribs essentially constitutes a dead space in which other components cannot be mounted, there isn't much space left for components within the case, and this wasted space makes it difficult to perform the subsequent mounting of additional components within the case.
In the scenario in which the material of a case is changed by the manufacturer to achieve increased rigidity, for example, if a polycarbonate composite containing glass fiber of 50 wt % or more is used, the case may exhibit lower shock resistance, although the rigidity of the case is greatly increased, which may frequently cause damage, such as cracks and the like, due to shock.
In addition, the use of glass fiber content proportionally increases the difficulty of painting the case. In particular, if the glass fiber is exposed to the outside due to abrasion damage to the case, the glass fiber has a high possibility of causing the user to have itchy skin.
Nowadays, an audio function has become an important function of portable electronic devices, particularly as multimedia messages are becoming more common, and a speaker has been mounted in the case to output sound to the outside of the device. However, since space for installation of the speaker, as well as resonance of sound generated from the speaker, is restricted due to the thickness or size of portable electronic devices and various functional components thereof, there is a problem in that the transmission distance of sound output from the speaker is short.